1. Field of the Invention
This invention relates generally to apparatus for inserting a plurality of pins or posts into holes in a substrate, and more particularly to a single tool or device for providing tip control and insertion capability for mounting pins or posts in holes of a substrate, such as a printed circuit board.
1. Description of the Prior Art
In the formation of printed circuit boards, which are of widespread popularity and usage, conductor leads ordinarily are formed on an insulative substrate by photo etching, or other well known techniques. Usually it is desired to make external attachment to the conductors of the printed circuit board for such purposes as applying power from a power supply or the like or establishing conduction paths between related circuit boards and other electrical circuitry.
One way in which attachment to the conductors of the printed circuit boards is achieved is by providing a plurality of pins or posts which are outstanding from the printed circuit board and to which connection can be made by soldering connection, or by suitable mating plugs or by other well known techniques. The positions of such posts or pins on the board are determined by the circuit paths printed on the board. Such circuit paths are often designed so that the posts are positioned in a straight line on the board and spaced apart equal distances. Holes are provided through the printed circuit board substrate to receive the pins, and are usually plated through with the printed circuit board conductor material to enhance the final electrical connection between the pins and the associated printed circuit board conductive path.
In the insertion of the pins or posts into the holes of the printed circuit board substrate, several techniques are typically used. Quite often the pins are individually hand inserted into the printed circuit board. Also, machines have been employed for automatic insertion of the pins, one by one, into the holes of the printed circuit board. In either process, a considerable amount of time is involved in completing the insertion process prior to subsequent completion steps such as wave soldering or other well known methods.
To expedite the insertion processes, a pin "comb" arrangement has been developed in which a plurality of side-by-side pins are carried on a common, continuous mounting strip. Typically, such pin combs are stamped or machined from a single piece of conductive material, such as copper, or the like and physically resemble a common hair comb. Also, such pin combs are often of relatively thin thickness, being on the order, for example, of 1/32 of an inch or less. This causes handling difficulties in inserting the pins, especially when the mounting strip extends over a length of several inches, since the pins tend to have a considerable degree of flexibility upon the mounting strip.
In the past, two individual tools have been used in sequence in the insertion of the pins of such pin comb into the board. First, a combining tool is employed to straighten and align the pins and hold them for partial insertion into the holes of the printed circuit board substrate. The combing tool is then removed and a push blade and a carrier control blade assembly is applied to complete the insertion. The combing tools commonly used are configured much like a pair of pliers having elongated U-shaped jaws. The U-shaped jaws are much like an elongated pair of tweezers having serrations formed on their inner surfaces to surround and grip the pins or posts, thereby straightening them upon the carrier and positioning them along the desired center line axis of the holes into which they are to be inserted.
After the combing tool has been removed, the plush blade and carrier control blade assembly is applied, as indicated. The push blade is simply an elongated member which is located adjacent the pins and their carrier. The carrier control blade is attached to the push blade, and is offset from the push blade to form a channel to receive the pin carrier or mounting strip. Thus, pressure can be applied to the push blade and carrier control blade to complete the insertion of the already partially inserted pins into the printed circuit board.
Because the prior art push blade and carrier control blade assembly is intended merely to engage the pin carrier strip, it affords control for the center line alignment and the tip straightening functions necessary for gang insertion of the pins, which functions are subsequently performed by a separate combing tool. Thus, in the prior art, two separate tools each requiring individual manipulation are required to achieve the desired gang insertion of the pin assembly and carrier into the printed circuit board.
It can be seen that this prior art two step assembly operation requires time for interchange of the tools, or at least additional personnel to efficiently effect gang insertion of the posts.